Arsenal completely failed to learn the lessons of the last-minute goal conceded against AZ Alkmaar and threw away a two-goal lead against West Ham at Upton Park yesterday. It was an exasperating outcome which meant that rather than finishing the day within striking distance of the top of the table, the Gunners had to content themselves with lurking in third, five points off the pace with a game in hand.

Yesterday's performance was arguably the weakest overall display the team has turned in this season. Even when they lost to United and City, they showed a good deal more spark and purpose in those matches than they mustered at the Boleyn Ground.

Just as it seemed that Arsenal had done enough to win an untidy match against AZ Alkmaar in Holland on Tuesday night, hesitant defending from a free kick allowed the Dutch side the opportunity grab a late equaliser. The Gunners had to settle for a point when they really ought to have taken three but it was an outcome that should not do any serious damage to their qualification hopes or, indeed, their chances of winning the group.

Though Arsene Wenger’s men dominated the ninety minutes and, for the most part, looked good value for a win, the late concession of a goal ought to serve as a timely reminder that, for all their sumptuous attacking play, defensive miserliness is just as important a facet for any successful team. The beautiful simplicity of Cesc Fabregas's goal underlined the team’s brilliance going forward but this was counter-balanced by the team's failure to defend a route-one set-piece at the death. From a speculative punt into the area, Granziano Pelle was allowed an unchallenged header and he nodded the ball into the path of Mendes da Silva who simply ran behind the static Alex Song to volley home. Though the players might have been looking around at each other after the ball hit the net, replays showed a catalogue of collective and individual errors.

After an interminably boring international break, it was a return to real football this weekend and the Gunners got straight back into their Premier League stride with a 3-1 victory over Birmingham City that sent them into the top four with a game in hand on the leaders.

Two first-half goals in quick succession from Robin Van Persie and Abou Diaby seemed to put Arsenal firmly in charge of yesterday’s match. From there, everyone expected the team to go on to rack up a score against a Birmingham side who spent most of the first forty five minutes penned in their own half. But, a combination of Arsene Wenger's men taking their foot off the gas and a moment of extremely weak goalkeeping from Vito Mannone allowed the Blues back into the contest as Lee Bowyer pegged a goal back in the 38th minute.

Six goals from six different players at Ashburton Grove on Sunday was the product of a sensational attacking performance by the Gunners as they thrashed Blackburn and signed off for the international break on a high. Any complaints about the Arsenal defending - which was well below par - were completely drowned out by the symphony of goals at the other end.

Despite Blackburn taking the lead twice in the first half, Arsenal had plenty in the tank by way of response. Their approach play and finishing was simply breathtaking at times and the performance - at least from an offensive perspective - was an appropriate one to mark a week that saw Arsene Wenger become the longest-serving manager in the club’s history after his 13 years in charge.

Sam Limbert: My retirement as a football player came at the age of 14 due to being rubbish, it's fair to say I was more Kaba Diawara than Thierry Henry, so I turned my focus to writing about the game. I'm a lifelong Arsenal fan and have been lucky enough to watch the team across England and Europe. My favourite Gunner of all time is Dennis Bergkamp, and the 2004 Invincibles is the greatest side I've ever seen in English football. I try to be positive about the Arsenal as it's the hope that keeps us going! Follow me on twitter @SamsMatchReport.